Endoscopic manual control knob, and a method for manufacturing same

ABSTRACT

An endoscopic manual control knob which has a knob body proper in the form of a synthetic resin molding. The knob body is largely composed of a ring-like top plate and a peripheral side wall portion fringed along outer periphery of the top plate. The top plate is provided with an aperture to be fitted on a rotatable shaft, and a number of lever portions projecting radially outward from the outer periphery of the top plate at angularly spaced positions. The knob body has an implant block embedded in each one of the lever portions by insert molding.

BACKGROUND OF THE INVENTION

1. Field of the Art

This invention relates to a manual control knob for an endoscope, andmore particularly to a manual control knob to be mounted on amanipulating head assembly of an endoscope for angularly bending a foreend portion of an insertion instrument, and a method for manufacturingsuch endoscopic manual control knob.

2. Prior Art

Endoscopes have been and are widely used in medical purposes. In mostcases endoscopes are constructed as shown schematically in FIG. 5,including a manipulating head assembly 1 to be gripped by an operator,an insertion instrument 2 which is extended out on the front side of themanipulating head assembly 1, and a universal cable 3 which is led outon the rear side of the manipulating head assembly 1. Provided at thefore distal end of an elongated flexible body portion 2 c of theinsertion instrument 2 is a rigid tip end section 2 a with anillumination window or windows along with an endoscopic observationwindow for endoscopic observation purposes. Further, provided betweenthe rigid tip end section 2 a and the flexible body portion 2 c is anangle section 2 b which can be angularly bent by remote control to turnthe rigid tip end section 2 a into an arbitrary direction. On the otherhand, the universal cable 3 is provided to connect the manipulating headassembly 1 at least with a light source.

As well known in the art, the angle section 2 b of the endoscopicinsertion instrument 2 has a flexible articulate structure which can bebent at least in one direction by remote control. Normally, the anglesection 2 b is arranged to be bendable in four directions, i.e., inupward, downward, rightward and leftward directions. The angle section 2b is bent in one of these directions by way of an angle manipulationmechanism which is provided on the manipulaing head assembly 1 of theendoscope.

Shown in FIG. 6 is an angle manipulation mechanism. As clear therefrom,a support plate 5is provided internally of the manipulating headassembly 1 to mount thereon a tubular support column 6, which rotatablysupports a pair of upper and lower pulleys 7 and 8. Upon rotating one ofthe two pulleys 7 and 8, say, the pulley 7 about the support column 6,the angle section 2 b of the insertion instrument is bent laterally in arightward or leftward direction. Upon turning the other one of thepulleys 7 and 8, say, the pulley 8 about the support column 6, the anglesection is bent vertically in an upward or downward direction. In orderto bend the angle section 2 b in this manner by remote control, a pairof upper and lower operating wires 9 are connected to the pulley 7,while another pair of right and left operating wires 10 are connected tothe other pulley 8.

The pulleys 7 and 8 are connected to hollow inner and outer rotatableshafts 11 and 12, respectively. The pulley 7 which is located on theside of the support plate 5 is connected to the inner rotatable shaft11. The pulley 8 which is located on the upper side of the pulley 7 isconnected to the outer rotatable shaft 12. These rotatable shafts 11 and12 are provided coaxially with the support column 6, and are led out tothe outside of a casing of the manipulating head assembly 1 of theendoscope. Manual control knobs 13 and 14 are connected to outer ends ofthe rotatable shafts 11 and 12, respectively.

When the insertion instrument 2 is introduced into a body cavity, whilegripping the manipulating head assembly 1 at the upper end of theinsertion instrument, an operator can manipulate the manual controlknobs 13 and 14 of the angle manipulation mechanism 8 to bend the anglesection of the insertion instrument in a desired direction. The anglemanipulation mechanism 4 is provided with lock means 15 and 16 therebyto lock the knob members 13 and 14 against rotational movements forretaining the angle section 2 b in a bent state whenever necessary.

The manual control knob 14 which is adopted for bending the anglesection 2 b in upward and downward directions is shown more particularlyin FIGS. 7 and 8. In these figures, indicated at 20 is a molded knobbody proper of the manual control knob 14. Through a link member 21, theknob body 20 is securely fixed to the rotatable shaft 12 by means of ascrew 22. The knob body 20 is provided with an aperture 23 in its topplate portion 20 a to receive the rotatable shaft 12, and theabove-mentioned link member 21 is connected to the top plate portion 20a. A peripheral side wall portion 20 b is contiguously provided aroundouter periphery of the top plate portion 20 a. These top plate portion20 a and the peripheral side wall portion 20 b are formed integrally bysynthetic resin molding. The molded knob body 20 is provided with aplural number of lever portions 24, which are projected radially outwardfrom a plural number of positions (five angularly spaced positions inthe particular example shown) around the outer periphery of the knobbody 20. For turning the knob body 20, an operator puts his or herfingers on the lever portions 24 and push the lever portions 24 to turnthe knob body 20 in a desired direction. For this purpose, finger gripsurfaces 24 a are provided on outer distal end faces of the leverportions 24. In the following description, the molded knob body 20 isassumed to have the top plate portion 20 a on the top side, and theoutwardly projected lever portions are regarded as outer peripheralportions of the knob body.

In order to turn the manual control knob 14 (or the other manual controlknob 13), while gripping the manipulating head assembly 1 of theendoscope in one hand, an operator can put his or her thumb on one ofthe finger rest surfaces 24 a in outer peripheral portions of the knobbody 20 to apply a force in a direction the knob member 14 is to beturned. Accordingly, in order to permit an operator to apply asufficient operating force easily on the knob member 14, it is desirablefor the knob body to have a broad finger grip surface on the leverportions. Namely, the finger grip surface 24 a on the lever portion 24should have not only a sufficient breadth in the circumferentialdirection but also a sufficient height (in a direction substantiallyparallel with the longitudinal axis of the rotatable shaft 12).

The top plate portion 20 a and the peripheral side wall portion 20 b ofthe knob body 20 are formed integrally together by synthetic resinmolding, providing lever portions 24 with finger grip surfaces 24 a of alarge breadth both in circumferential and axial directions. In case theknob body 20 is molded to have solid lever portions 24, there may arisea problem of shrinkage surface sinking, which often results in sunkenspots on the surfaces of molded lever portions 24. Such surface sinkingcan impair the maneuverability and appearance of the knob members to aconsiderable degree especially in case sunken spots exist on thesurfaces of the lever portions 24. The problem of shrinkage surfacesinking has thus far been prevented by reducing the thickness of the topplate portion 20 a and side wall portion 20 b of the knob body 20 to aminimum necessary thickness which would be allowable in terms ofstrength, as shown in FIG. 8.

The lever portions of the knob members, especially the finger gripsurfaces of the lever portions which are repeatedly touched by thefingers of an operator get contaminated easily. Normally, each time anendoscope is washed clean after use. More particularly, an endoscope iswashed by immersing the entire body of the endoscope in a cleaningliquid, including not only the insertion instrument, which has beendirectly introduced into a body cavity, but also the manipulating headassembly and the universal cable of the endoscope. At this time, themanual control knobs of the angle manipulation mechanism are also washedin the cleaning liquid. However, it is often found difficult to cleanback side of the respective lever portions and corner portions betweenthe top plate portion and the side wall portion of the knob member to asatisfactory degree.

In an attempt to overcome the above-mentioned problem or difficulty, ithas been known, for example, from Japanese Laid-Open Patent ApplicationH11-47082 to fill cavity on the back side of each lever portion with aback nail member in the form of a block of the same synthetic resinmaterial as the knob body and welded to the latter. Namely, in thiscase, while reducing the wall thickness of the knob body to a minimumnecessary thickness which is free of shrinkage surface sinking in amolding stage, the hollow cavity on the back side of each lever portionof the molded knob body is completely filled and closed with the backnail member.

However, in the case of the prior art knob construction just mentioned,the fabrication process becomes complicated and involves an increasednumber of steps because of the necessity for a step of molding the backnail members in addition to the molding of knob bodies and a step ofwelding molded back nail members to the back side of the respectivelever portions of the knob body. This naturally results in increases inproduction cost. Besides, unless the back nail members are thoroughlywelded to a knob body, there are possibilities of contaminants stillremaining in interstices or devises at incompletely welding portionseven after a careful cleaning or washing operation.

SUMMARY OF THE INVENTION

With the foregoing situations in view, it is an object of the presentinvention to provide an endoscopic manipulation knob of synthetic resinmolding, which is provided with substantially solid lever portions freeof sunken surface spots or other irregularities and which can beproduced in a facilitated manner.

It is another object of the present invention to provide an endoscopicmanipulation knob of synthetic resin molding, which is arrangedespecially to get rid of unwashed or unclean spots on or in the vicinityof finger grip surfaces of the knob.

In accordance with the present invention, in order to achieve theabove-mentioned objectives, there is provided a manual control knobsuitable for use on an endoscope for manipulation of an insertioninstrument, the manual control knob being of the sort having a knob bodyof synthetic resin molding largely constituted by a ring-like top plateand a peripheral wall portion of a predetermined width formed integrallyalong marginal edges of the top plate, an aperture perforated centrallythrough the top plate, a plural number of lever portions projectedradially outward from angularly spaced positions around outer peripheryof the top plate, each one of the lever portions being provided with afinger grip surface at an outer distal end, and the aperture of the topplate being fitted on a rotating shaft projected from a manipulatinghead assembly of the endoscopic insertion instrument, characterized inthat: the knob body is constituted by a synthetic resin molding havingthe top plate and the peripheral side wall portion molded integrallywith each other and having implant blocks embedded in the lever portionsof the top plate by insertion molding; and cover wall portions areformed integrally with the knob body to enshroud the implant blockscompletely on a lower back side of the knob body facing away from thetop plate.

In this instance, it is desirable that inner peripheral side walls ofthe implant blocks be at least partly enshrouded by an enfolding wallportion which is formed integrally with the cover wall portion. The knobbody and the implant blocks may be formed of the same synthetic resinmaterial if desired. However, different synthetic resin materials may beemployed for these parts to impart different properties. For example, itis important to form the knob body by the use of a synthetic resinmaterial with high resistance to chemicals. On the other hand, theimplant blocks can be formed either by the use of the same syntheticresin material as the knob body or by the use of hard plastics. Further,it is desirable to provide positioning projections on each one of theimplant blocks to prevent same from falling when inserted into a mold asan insert at the time of molding the knob body.

Furthermore, according to the present invention, there is also provideda method for manufacturing a manual control knob suitable for use on anendoscope for manipulation of an insertion instrument, the manualcontrol knob being of the sort having a knob body of synthetic resinmolding largely constituted by a ring-like top plate and a peripheralwall portion of a predetermined width formed integrally along marginaledges of the top plate, an aperture perforated centrally through the topplate, a plural number of lever portions projected radially outward fromangularly spaced positions around outer periphery of the top plate, eachone of the lever portions being provided with a finger grip surface atan outer distal end, and the aperture of the top plate being fitted on arotating shaft projected from a manipulating head assembly of theendoscopic insertion instrument, the method comprising the steps of:preparing an insert member having a plural number of implant blocks atouter distal ends of radial connecting arms extending radially outwardfrom a center core; setting the insert member within a cavity of a moldin a molding stage of the knob body, in such positions that therespective implant blocks of the insert member a re located in leverportions to be formed; introducing a synthetic resin material into themold to form the knob body on the insert member, having the implantblocks completely embedded in the lever portions of the knob body by acover wall portion formed integrally with the knob body to cover lowerside of the implant blocks remote from the top plate of the knob body;and cutting off at least radial connecting arm portions falling withinboundaries of the aperture in the top plate.

The above and other objects, features and advantages of the presentinvention will become apparent from the following particulardescription, taken in conjunction with the accompanying drawings whichshow by way of example preferred embodiments of the invention. Needlessto say, the present invention should not be construed as being limitedto the particular forms which are shown in the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is a schematic bottom view of a knob body embodying the presentinvention;

FIG. 2 is a schematic sectional view taken on line X-X in FIG. 1;

FIG. 3 is a schematic plan view of insert members;

FIG. 4 is a schematic sectional view taken on line Y-Y of FIG. 3;

FIG. 5 is a schematic illustration showing the general layout of anendoscope;

FIG. 6 is a schematic sectional view taken through an angle manipulationmechanism which is provided in the endoscope of FIG. 5;

FIG. 7 is a schematic bottom view of a knob body by prior art; and

FIG. 8 is a schematic sectional view taken on line Z-Z of FIG. 7.

DESCRIPTION OF PREFERRED EMBODIMENTS

Hereafter, the present invention is described more particularly by wayof its preferred embodiment shown in the accompanying drawings. Theendoscope as well as the angle manipulation mechanism which appear inthe following description is conventional in general construction andhas no differences in particular from the counterpart in the prior artwhich is described hereinbefore. The knob construction according to thepresent invention is applied to an operating knob of an anglemanipulation mechanism of an endoscope in the following description.Needless to say, the knob construction according to the presentinvention can also be applied similarly to a knob for raising theposture of an inserted tool or the like.

Shown in FIGS. 1 and 2 is the construction of a knob body according tothe present invention. In these figures, indicated at 30 a is a topplate portion and at 30 b a circumventive side wall portion. The topplate portion 30 a is provided with an aperture 31 in its center portionto receive a rotatable shaft therein as indicated as 12 in FIG. 6.Further, a plural number of screw receptacle holes 32 are provided inthe vicinity of the aperture 31 in the top plate portion 30 a to receivescrew members which connect the top plate to a link member (a memberequivalent to the link member indicated at 21 in FIG. 6) serving to fixthe top plate member 30 a to the rotatable shaft. The top plate portion30 a and the peripheral side wall portion 30 b of the knob body 30 areintegrally formed by synthetic resin molding. The knob body 30 isprovided with a plural number of radially projecting lever portions 33(e.g., five lever portions 33 in the particular embodiment shown) atangularly spaced positions, namely, at angular intervals around outerperipheries of the top plate portion 30 a and the peripheral side wallportion 30 b. At a projected distal end, each one of these leverportions 33 is provided with a finger grip surface 33 a which has asufficient breadth in both axial and circumferential directions. Thewidth of each lever portion 33 is gradually increased in a radiallyinward direction or in a direction away from the finger grip surface 33a. Accordingly, the peripheral side wall portion 30 b contains fivearcuately indented portions at angularly spaced positions.

An implant block 34 is embedded in each lever portion 33 to provide asubstantially solid lever structure. On the side away from the top sidewhich is joined with the top plate portion 30 a, that is to say, on thelower side, the implant block 34 is completely covered with a cover wallportion 35 which is formed integrally with the peripheral side wallportion 30 b. Furthermore, the part of a radially inner end face of theimplant block 34 is covered in a hem portion which is formed integrallywith the afore-mentioned cover portion 35. Extended out from theradially inner end face of each implant block 34 is a connecting arm 37which is connected with other arms 37 from other implant blocks 34 atthe center of the knob. Each one of the implant blocks 34 is providedwith positioning projections 38 on an inner peripheral surface on theopposite sides of the connecting arm 37 as shown in FIG. 3 thereby toprevent the implant block 34 from being destabilized and caused to falldown under pressure of a supplied synthetic resin in an insert-moldingstage which will be described hereinlater.

The implant blocks 34 which are completely embedded in the leverportions 33 of the knob body 30 as an insert at the time of molding theknob body 30. Shown in FIGS. 3 and 4 is an insert member 40 to be usedin insert molding for embedding the respective implant blocks 34 in thelever portions 33 of the knob body 30.

The insert member 40 is composed of a core member 39, a plural number ofconnecting arms 37 which are extended radially outward from the coremember 39 at angularly spaced positions, and implant block members 34which are connected to outer distal ends of the connecting arms 37. Asmentioned hereinbefore, each one of the implant blocks 34 is providedwith positioning projections 38 on its inner peripheral surface which isconnected to the arm 37. Both of the connecting arm 37 and positioningprojections 38 are arranged to fall short of the lower end of theimplant block 34 in vertical length. Therefore, the lower end of theimplant block contains no projected portions over a predetermined width.

Described below is a method for molding the knob body 30 having theimplant blocks 34 inserted therein. In the first place, the insertmember 40 is prepared, for example, by synthetic resin injectionmolding. In this respect, shrinkage surface sinking may occur to theimplant blocks 34 which form large masses on the insert member 40.However, existence of sunken surface spots on the implant blocks 34gives rise to no problem because the implant blocks 34 are eventuallycompletely embedded in lever portions of the knob.

The implant blocks 34 which are provided as functional parts on theinsert member 40 are each connected to the core member 39 through theconnecting arm 37. Therefore, the insert member 40 can be extremelyeasily set in a mold to be used for injection molding of the knob body30. Besides, the core member 39 can be utilized as a registration meansin positioning the insert member 40 within the mold. It follows that theinsert member 40 can be easily set in position within the mold prior tomolding the knob body 30.

The implant blocks 34 to be located in peripheral portions of the knobbody 30 are each connected to an outer end of a long connecting arm 37,and are preferably formed in a minimum necessary thickness. This meansthat the implant blocks 34 can be caused to fall to one side or can bedeviated in position under the influence of supplied resin pressure inthe stage of molding in the insert member. However, the respectiveimplant blocks 34 are restricted of movements and retained in positionwithin a mold cavity in an extremely stabilized state thanks to theprovision of the positioning projections 38 on the inner peripheralsurfaces of the respective implant blocks 34.

The knob body 30 is formed by injection molding. Therefore, no matterwhether or not the positioning projections 38 are provided on the insertmember 40, it is desirable to select for the insert member 40 a materialwhich has sufficiently high rigidity free of deformations under moldingpressure. More preferably, the insert member 40 is formed of a materialwhich is sufficiently high in rigidity and at the same time light inweight. On the other hand, the knob body 30 which is largely exposed tothe outside should be formed of a material which has high resistance tochemicals. In this regard, examples of suitable material for the knobbody 30 include noryl, polyether imide, polysulfone, polyphenylsulfoneand the like. Further, the insert member should preferably haveresistance to chemicals as well because it is exposed to the outside atleast in part. Accordingly, usually the same material as the knob body30 is selected fro the insert member 40. However, a different materialmay be selected arbitrarily for the insert member 40 as long as it hasthe required properties in resistance to chemicals, rigidity andlightness.

The insert member 40 is integrally molded into the knob body 30 at thetime of molding the top plate portion 30 and the peripheral side wallportion 30 b of the knob body 30. At this time, the cover portion 35 isformed integrally with the peripheral side wall portion 30 b on thelower side of the implant blocks 34 (that side which is located awayfrom the top plate portion 30 a), and the inner enfolding wall portion36 is formed integrally on the inner peripheral surface of the implantblocks 34. The lower cover wall portion 35 and the inner enfolding wallportion 36 are formed continuously from the peripheral side wall portion30 b of the knob body 30, and no boundary exists between these parts.

In this instance, the peripheral side wall portion 30 b of the knob body30, more particularly, the finger grip surface 33 a on the lever portion33 is preferably inclined to present an outwardly diverging shape in thedownward direction, from the standpoint of enhanced maneuverability. Theimplant blocks 34 on the insert member 40 are preferred to be inclinedin a similar shape so that the peripheral side wall portion 30 b can beformed substantially in uniform thickness and its wall thickness can bereduced since it is held in intimate contact with the implant blocks 34.

Upon completion of the molding of the knob body 30 having the insertmember 40 implanted therein, the molded knob structure is ejected fromthe mold and then the aperture 31 is opened in the top plate portion 30a by cutting and removing a corresponding part of the top plate 30 a ofthe knob body 30. As a result, there is obtained a knob body 30 withsubstantially solid lever portions 33 each having an implant block in acompletely embedded state.

The knob body 30, which is obtained by the insert molding as describedabove, is provided with substantially solid lever portions 33, and issatisfactory in surface accuracy because there is little possibilitiesof surface sinking occurring to the top plate portion 30 a and theperipheral side wall portion 30 b of the knob body 30 which arerelatively small in wall thickness. In the endoscopic angle sectionmanipulating mechanism as shown in FIG. 5, the knob body 30 can beconnected to the rotatable shaft 12 through a link member to serve as acontrol knob 17. When an operator feels the necessity for bending theangle section of an endoscopic insertion instrument, the operator putshis or her fingers on the finger grip surfaces of the solid leverportions 33 of the knob body 30 for turning same. On such an occasion,the control knob 17 can be manipulated with better maneuverability,without experiencing a feeling of clumsiness.

When manipulated by an operator, the knob body 30 can be contaminated asa result. Contamination is most likely to occur on and in the vicinityof the finger grip surfaces 33 a of the lever portions 33. In thisinstance, almost the entire outer surface of each lever portion 33 isconstituted by the top plate portion 30 a and the peripheral side wallportion 30 b and at the same time by the back cover wall portion 35 andthe enfolding wall portion 36 which are formed integrally with the topplate portion 30 a and the peripheral wall portion 30 b. That is to say,the surface of each lever portion 33 of the knob body 30 contains noseams, sunken spots or joint portions. Therefore, deposited contaminantscan be easily removed from the knob body 30 by immersion in a cleaningliquid. In other words, the control knob of the endoscope is extremelyfavorable in terms of washability and disinfection factor. Although astepped surface portion exists between the upper end of the enfoldingwall portion 36 and a wall surface on the inner peripheral side of theimplant block 34, there is little possibility of contaminants getting toand stagnating on the stepped surface portion which is located in a deepportion of the knob body 30.

Subsequent to the insertion molding, the connecting arms 37 of theinsert member 40 are cut off except the arm portions which remainradially on the outer side of the aperture 31 in the top plate portion30 a of the knob body 30. Of course the connecting arms 37 may be cutoff completely if desired. However, in case the arm portions radially onthe outer side of the aperture 31 are left as reinforcing ribs, itbecome possible to further reduce the wall thickness of the top plateportion 30 a of the knob body 30. In addition, in connecting the knobbody 30 to the rotating shaft 12 through a link member, the portions ofthe arms 37 can be utilized as an anti-rotation mechanism which preventsrelative rotational movements between the knob body 30 and the linkmember.

1-9. (canceled)
 10. A method for manufacturing an endoscopic manualcontrol knob to be used on an endoscope for manipulation of an insertioninstrument, said manual control knob being of the sort having a knobbody of synthetic resin molding largely constituted by a ring-like topplate and a peripheral wall portion of a predetermined width formedintegrally along marginal edges of said top plate, an apertureperforated centrally through said top plate, a plural number of leverportions projected radially outward from angularly spaced positionsaround outer periphery of said top plate, each one of said leverportions being provided with a finger grip surface at an outer distalend, and said aperture of said top plate being fitted on a rotatingshaft projected from a manipulating head assembly of said endoscopicinsertion instrument, said method comprising the steps of: preparing aninsert member having a plural number of implant blocks at outer distalends of radial connecting arms extending radially outward from a centercore; setting said insert member within a cavity of a mold in a moldingstage of said knob body, in such positions that the respective implantblocks of said insert member a re located in lever portions to beformed; introducing a synthetic resin material into said mold to formsaid knob body on said insert member, having said implant blockscompletely embedded in said lever portions of said knob body by a coverwall portion formed integrally with said knob body to cover lower sideof said implant blocks remote from said top plate of said knob body; andcutting off at least radial connecting arm portions falling withinboundaries of said aperture in said top plate.